Since Real Madrid won Girona, they have not been consistent in the league. I agree with you that Girona might play in the European League if they continue with their current inconsistency. If Barcelona overtakes Girona in the La Liga table, Girona will not handle the pressure from Athletico Madrid and Athletic Bilbao to finish in the top four of La Liga.
This could indeed be possible for Girona, but to just stay in the top four of the La Liga standings, I think Girona will also be able to maintain this this season. Because remembering that currently Girona is still in second place even though they have lost at home to Getafe and even though Barcelona also has the opportunity to take Girona's position today. I still think that it will be a little difficult because considering that the opponent that Barcelona will face today is Atletico Madrid who will be the hosts of today's match.